Glucagon-like peptide-1 (GLP-1) is an important gastrointestinal hormone that has a control function in glucose metabolism, and gastrointestinal secretion and metabolism. GLP-1R is a GLP-1 receptor, which is a seven-transmembrane G protein-coupled receptor.
As a imaging molecular probe that binds to GLP-1R as a target molecule, a peptide, such as GLP-1, Exendin-3, Exendin-4, Exendin(9-39), or a variant thereof that is labeled by labeling molecule is being studied (Patent Document 1, for example).